1. Field of the Invention:
The invention pertains to miniature image viewers and more particularly to an image viewer having a scannable lens assembly which is of variable field and variable magnification.
2. Description of the Prior Art:
This application presents an improvement in the concept of the miniature hand-held viewer described in the above identified previously filed applications. The purpose of that device was to provide a portable image viewer wherein a large quantity of information could be kept readily at hand on microfilm type transparencies. The viewer described was particularly useful for transporting and viewing miniature maps in the field by explorers, hikers, sailors and the like. In using the maps, it has been found desirable to view a large area of the map at one level of magnification and then to view particular segments at a higher magnification in order to analyze the surrounding terrain in greater detail.
To accomplish this, a scannable lens assembly having a variable field and variable magnification has been devised and is described herein. The inventor knows of no similar device existing in the prior art.